The stripping of a cable using a cable stripping tool necessitates the following working steps:
First the cable is inserted into the cable stripping tool in an insertion position of the cable stripping tool.
Then a clamping of the cable and an at least partial severing of the insulation encasing the conductor takes place in a cutting stroke, in which knives are moved with a movement being directed radially to the longitudinal extension of the cable.
Finally in a cable stripping stroke the knives placed in the cuts of the encasing insulation are moved in a direction being coaxial to the longitudinal axis of the cable. By this movement the axial portion of the encasing insulation severed in the cutting stroke and related to the free end of the cable is pulled off the conductor line located therein.
For enabling the cutting stroke on the one hand and the cable stripping stroke on the other hand, hand levers of known cable stripping tools operate a gear drive, which for inducing the cutting stroke causes a pivoting motion of pliers jaws towards each other in a pivot plane and on the other hand for the cutting stroke causes an movement of a draw shackle having an orientation coaxial to a longitudinal axis of the cable. A cable stripping unit formed with two cable stripping jaws is housed between the pliers jaws in such a way that during the cutting stroke the pivoting of the pliers jaws towards each other also causes a pivoting of the cable stripping jaws towards each other. On the other hand the cable stripping unit is supported slidingly with respect to the pliers jaws so that during the cable stripping stroke (at unchanged pivot angles of the pliers jaws as well as of the cable stripping jaws) a sliding movement of the cable stripping unit having an orientation coaxial to the longitudinal axis of the cable can be caused by the movement of the draw shackle linked to the cable stripping unit. The cable stripping jaws of the cable stripping unit in the end portion facing away from the linking point of the draw shackle support the knives. On the one hand the knives are responsible for cutting of the encasing insulation. On the other hand the knives also serve for the pulling-off of the axial portion of the encasing insulation. Such cable stripping tools are known for example from the documents DE 42 05 194 C1; EP 1 324 448 A2 (corresponding to U.S. Pat. No. 6,910,401 B2), DE 20 2008 014 110 U1 (corresponding to U.S. Pat. No. 7,913,588 B2) and U.S. Pat. No. 4,485,696 A.
Due to wear of the knives an exchangeability of the cable stripping unit or of the knives is desired. It is also possible that (dependent from the intended use of the cable stripping tool) usage with different knives might be desired. For example for usage of the cable stripping tool for cables with different diameters of the conductor and/or of the insulation or different types of cables the use of different cable stripping units or knives might be necessary. It is possible, for example, that with the same cable stripping tool the alternative use of knives                which are formed with separate, possibly resiliently supported lamellae,        which have a straight cutting edge,        the cutting edge of which is adapted to the contour of the insulation or the conductor,        which are formed with two knife blades with cutting edges inclined towards each other in a V-shape, and/or        which are formed with a cutting edge which has several concavely arched blade portions next to each other for cables of differing cross sections        
is to be enabled.
In order to ensure an exchangeability of the knives the document DE 20 2008 000 596 U1 (corresponding to U.S. Pat. No. 7,900,537 B2) suggests that into the cable stripping jaws connected pivotably with the draw shackle on the inner sides turned towards each other a knife cassette each can be inserted. The knife cassettes have side walls, which in their mounted state are housed between the respective side walls of the cable stripping jaws. A latching is achieved between the side walls of the knife cassette and the respective cable stripping jaw. For this purpose in the knife cassette a wire spring bent into a U-shape is supported, the end portions of which extend from the front side of the knife cassette. In the latched state the base arm of the U of the wire spring engages into a slit of the side wall of the cable stripping jaw. For release of the latching and removal of the knife cassette from the cable stripping jaws it is necessary that the user presses the end pieces of the wire springs extending from the front side of the knife cassette towards each other in such a way that the base arm of the U of the wire spring exits from the slit of the cable stripping jaw.
DE 20 2008 014 111 U1 (corresponding to U.S. Pat. No. 7,841,260 B2) describes an exchange of the knives by an exchange of the cable stripping jaws. For this purpose it is necessary that a bearing bolt which fixes a pliers jaw is demounted from the cable stripping tool. Only then pivoting of an upper cable stripping jaw upwards is possible so that the cable stripping jaw can be removed from a yoke of the draw shackle. For an upper cable stripping jaw demounted in this way the lower cable stripping jaw can also be pivoted upwards and then also be removed from the yoke of the draw shackle. Subsequently other cable stripping jaws with knives with a different cutting-edge shape can be mounted with the yoke of the draw shackle.
From a brochure of the company Weidmëller with brochure No. 1132660000/07/2009/SMMW a cable stripping tool marketed under the trademark “STRIPAX®” is known. Here, a simple exchange of knives is intended to take place by first demounting the upper pliers jaw from the cable stripping tool. Subsequently the cable stripping unit with the two cable stripping jaws, which support the knives, can be removed from the cable stripping tool as a unit and exchanged by another cable stripping unit.
By the company JOKARI-Krampe GmbH a cable stripping tool “Sensor Special No. 20300” is marketed in which exchangeable knife blocks are held by pliers jaws. In this case the knife blocks are realized as massive metallic form pieces having a complex form, which integrally form the cutting edges as well as a mounting element built by a protrusion. The mounting element can be inserted into a mounting groove of the pliers jaws from the side in the direction of a mounting axis. In the mounted state of the knife blocks these are secured on the one hand by a two-component adhesive and on the other hand by securing clamps. The exchange of the knife blocks requires a plastic deformation of the securing clamps as well as loosening of the two-component adhesive.
From the brochure “2013/2014: Kabelverarbeitung” of the company RENNSTEIG Werkzeuge GmbH (printing identification “rwz 06-2013/A-5000”) a cable stripping tool marketed under the identification “MultiStrip 10” is known, in which the cable stripping unit formed with the pivotable cable stripping jaws is removable. Knives are each screwed to the front sides of the cable stripping jaws. Since the screws holding the knives in a mounted state of the cable stripping unit are covered by the pliers jaws and by the clamping jaws for the cable assigned to the pliers jaws, an exchange of the knives in any case requires a disassembly of the cable stripping unit.
The documents U.S. Pat. No. 5,713,132 A, U.S. Pat. No. 6,253,641 B1 and US 2011/0138629 A1 do not relate to cable stripping tools of the present type. Instead, the tools described in these documents only have a cutting stroke, but not a following cable stripping stroke caused by means of a drive. Accordingly, for these tools for a cable stripping the cable needs to be pulled manually while the insulation previously cut during the cutting stroke has to be held back by the cable stripping tool.